St. Petersburg, Florida (CNN) -- As if the pictures of birds, fish and animals killed by floating oil in the Gulf of Mexico are not disturbing enough, scientists now say they have found evidence of another danger lurking underwater.

The University of South Florida recently discovered a second oil plume in the northeastern Gulf. The first plume was found by Mississippi universities in early May.

USF has concluded microscopic oil droplets are forming deep water oil plumes. After a weeklong analysis of water samples, USF scientists found more oil in deeper water.

"These hydrocarbons are from depth and not associated with sinking degraded oil but associated with the source of the Deep Horizon well head," said USF Chemical Oceanographer David Hollander.

Through isotopic or microscopic fingerprinting, Hollander and his USF crew were able to show the oil in the plume came from BP's blown-out oil well. The surface oil's so-called fingerprint matched the tiny underwater droplet's fingerprint.

"We've taken molecular isotopic approaches which is like a fingerprint on a smoking gun," Hollander said.

Scientists on board the university's research vessel Weatherbird II were not able to find the dissolved hydrocarbon or oil by sight. Instead the crew received sensor signatures from the equipment deployed into the water since the plumes appear to be clear.